Tranexamic acid may promote melanocores clustering in keratinocytes through upregulation of Rab5b

Abstract

Melasma is a chronic acquired hyperpigmentation disorder typically manifesting as symmetrically distributed light to dark brown patches on the cheeks, forehead and jaws with irregular borders, 1 with a reported prevalence ranging from 1.5% to 33%, especially in child-bearing women, causing significant psychosocial impairment. 2 Predisposed genetic background, ultraviolet exposure and female hormone stimulation have been documented as the main pathogenic factors of melasma. 3 The pathogenesis of melasma has not been fully elucidated. An increasing body of evidence suggests that increased melanin synthesis due to increased activation of epidermal melanocytes is one of its most important pathogenic mechanisms. 4 In addition, dermal vascular proliferation, mast cell infiltration, fibroblast aging, basement membrane damage and epidermal barrier defective are all involved in the development of melasma. [5][6][7][8][9] Recent